CSU Stanislaus, Valley Flora Propagation Center Species Profiles winter, the plants go dormant and drop their leaves. Plants ATRIPLEX POLYCARPA (TORREY) S. WATSON will begin to display new growth during spring.

COMMON NAME: CATTLE SALTBUSH, ALLSCALE, SEED DORMANCY & GERMINATION CATTLE SPINACH According to Sankary & Barbour (1972), seeds of this FAMILY: AMARANTHACEAE (FORMERLY species do not exhibit dormancy. Professional germination CHENOPODIACEAE) tests performed on several of our A. polycarpa seed lots did not indicate any seed dormancy. Soaking seeds in water GROWTH FORM: SHRUB before sowing them has been recommended, in order to remove inhibitors (Graham, 2003). It has been demonstrated that plant-produced chemicals such as saponins can inhibit or reduce germination in A. polycarpa (Cornelius and Hylton, 1969, Askham and Cornelius, 1971).

SEED HARVESTING A. polycarpa seeds are enclosed within fruiting bracts. Fruits (utricles) are ready for collection when they are light yellow or light brown in color and have a hard consistency at their center. Immature fruits will have a soft consistency when squeezed between two fingers. We have noticed that the fruit size of A. polycarpa is quite variable between years. To harvest plant material, we would: 1) strip fruits off by hand; 2) shake fruits off branches into a collecting bag; or 3) clip off fruit-bearing branches. Because the seed collection window occurs during the winter monsoonal A. polycarpa at the Little Panoche Reservoir Wildlife Area period, rainfall can potentially disperse a portion of the fruits (managed by the California Department of Fish and Game). before they can be harvested. If plant material is wet when collected, it must be allowed to dry before seed processing PLANTING can begin. We would transport the harvested plant material to a warehouse and spread it out on tarpaulins to air dry. During January 2003, seeds were hand-sown onto We would set up a few electric fans to facilitate drying and mounded planting beds, and a thin layer of soil was then turn the plant material at least once a day. raked over them. The species was seeded heavily1 and germination was so dense that the plants had to be thinned SEED PROCESSING METHODS to prevent crowding. The first seed harvest from the plants was made during December 2004. During winter of 2004, Using a hammer mill, raw plant material is reduced into a seeds of A. polycarpa were sown in a different area of the coarse but uniform mixture of fruits, chaff (e.g., leaves, floral nursery. The Tranquillity area has a semi-arid climate with structures), and pieces of stems and branches. In order to low mean annual precipitation. However, both the 2002-03 completely remove fruits from branches and stems, we and 2004-05 growing seasons were favorable years for would sometimes run the plant material through the shrub establishment at the nursery. Total precipitation hammer mill several times. Seeds can then be separated received during the 2002-03 hydrologic year (1 August 2002 from chaff and woody material using an air screen cleaner through 31 July 2003), 17.6 cm, was 80.2% of the 30-year such as a Clipper Eclipse (made by the A.T. Ferrell mean2, and total precipitation received during the 2004-05 Company). hydrologic year, 28.2 cm, was 128.2% of the 30-year mean (California Irrigation Management Information System, CULTIVATION OVERVIEW Station #105). Numerous A. polycarpa individuals derived from two wild source populations have been established in the nursery PHENOLOGY since 2003, and they have reliably produced seed every We have observed A. polycarpa seedlings growing at the year. Individuals derived from a third wild source population nursery at several times throughout the year; the species have been established in the nursery since 2005. does not seem to require a high level of soil moisture for The species seems to tolerate growing at high density in the germination. When growing in the San Joaquin Valley, A. nursery, though we have observed that individuals growing polycarpa typically flowers during August and September in isolation are much larger (3 meters in diameter) than and will begin to form fruits by October. Peak time for seed individuals that are surrounded by other shrubs (1.5 meters collection is late November to mid-December. During in diameter). The species is well adapted to dry growing conditions; it has never appeared drought-stressed at the nursery and does not require any supplemental watering. 1 One large handful of seed (approximately 60% purity) per 0.5- Through seed dispersal, the species frequently became meter length of a planting bed. Viability of the seed lot was established in areas of the nursery where it had not been unknown. planted. We occasionally had to remove such „volunteer‟ 2 The annual and monthly means were calculated using 30 years of individuals when they encroached upon other cultivated precipitation data (1976-2006) from four weather stations native species. (Cooperative Station ID #‟s 43083, 45118, 45119, 45120) located in the western San Joaquin Valley. http://esrp.csustan.edu/vfpc 1 CSU Stanislaus, Valley Flora Propagation Center Species Profiles A. polycarpa is halophytic and would likely tolerate the PHOTOS elevated soil salinity that is characteristic of the retired agricultural lands in the western San Joaquin Valley. A horticultural entry included in The Jepson Manual recommends that A. polycarpa is an especially good species to use for stabilizing or restoring disturbed or degraded areas. However, the species is also described as potentially invasive due to its ability to outcompete or displace other species (Hickman, 1993).

REFERENCES Hickman, J. C. (editor). 1993. The Jepson manual: higher plants of California. University of California Press, Berkeley.

ADDITIONAL INFORMATION ABOUT ATRIPLEX POLYCARPA:

Internet Resources A. polycarpa volunteers growing at the native plant nursery. Plant Guide by the Natural Resources Conservation Service Through seed dispersal, the species frequently became established available at: http://plant- in areas of the nursery where it had not been planted. materials.nrcs.usda.gov/pubs/azpmcpg5107.pdf Propagation Protocol from the Native Plant Network (Graham, 2003): http://nativeplants.for.uidaho.edu/network/view.asp?protocol_ id=2587 Literature

Askham, L.R. and D.R. Cornelius. 1971. Influence of desert saltbush saponin on germination. Journal of Range Management 24:439-442. Chatterton, N.J. and C.M. McKell. 1969. Time of collection and storage in relation to germination of desert saltbush seed. Journal of Range Management 22:355-356.

Cornelius, D.R. and L.O. Hylton. 1969. Influence of temperature and leachate from seed on germination of Atriplex polycarpa. Agronomy Journal 61:209-211. Graves, W.L., B.L. Kay, and W.A. Williams. 1975. Seed treatment of Mojave desert shrubs. Agronomy Journal 67:773-777. Kay, B.L., C.C. Pergler, and W.L. Graves. 1984. Storage of seed of Mojave desert shrubs. Journal of Seed Technology 9: 20-28. Pater, M.J. and B.D. Munda. 1997. Pages 14-17 in: 1997- 1998 Annual Report. Tucson Plant Materials Center, Natural Resource Conservation Service. Available at: http://www.plant- materials.nrcs.usda.gov/pubs/azpmctr9798.pdf

Sankary, M. N. and M. G. Barbour. 1972. Autecology of Atriplex polycarpa from California. Ecology 53: 1155- 1162.

PREPARED BY Brianna D. Borders, Restoration Botanist. Other Contributors: Dr. Nur Ritter, Justine Kokx, Adrian Howard, and Graham Biddy. http://esrp.csustan.edu/vfpc 2 CSU Stanislaus, Valley Flora Propagation Center Species Profiles

A. polycarpa at the Little Panoche Reservoir Wildlife Area. A. polycarpa seed. Scale shown is millimeters.

Each A. polycarpa seed is enclosed within fruiting bracts. Scale shown is millimeters.

http://esrp.csustan.edu/vfpc 3